diff --git a/src/client/javascripts/geospatial-map.js b/src/client/javascripts/geospatial-map.js
index 5414237a1..b85d1a16b 100644
--- a/src/client/javascripts/geospatial-map.js
+++ b/src/client/javascripts/geospatial-map.js
@@ -490,7 +490,7 @@ function prepareGeometry(feature) {
  * @param {GeoJSON} geojson
  * @returns {FeaturesManager}
  */
-function getFeaturesManager(geojson) {
+export function getFeaturesManager(geojson) {
   /**
    * Get a feature from the geojson by id
    * @type {GetFeatures}
@@ -528,9 +528,9 @@ function getFeaturesManager(geojson) {
 
     // Ensure the feature exists in the geojson
     if (feature) {
+      feature.geometry = geometry
       feature.properties.coordinateGridReference = getCoordinateGridRef(feature)
       feature.properties.centroidGridReference = getCentroidGridRef(feature)
-      feature.geometry = geometry
       prepareGeometry(feature)
     }
 
diff --git a/src/client/javascripts/geospatial-map.test.js b/src/client/javascripts/geospatial-map.test.js
new file mode 100644
index 000000000..035fa44c5
--- /dev/null
+++ b/src/client/javascripts/geospatial-map.test.js
@@ -0,0 +1,191 @@
+import { getFeaturesManager } from '~/src/client/javascripts/geospatial-map.js'
+
+/**
+ * @param {string} id
+ * @param {Geometry} geometry
+ * @returns {Feature}
+ */
+function buildFeature(id, geometry) {
+  return {
+    id,
+    type: 'Feature',
+    properties: {
+      description: 'Survey location',
+      coordinateGridReference: '',
+      centroidGridReference: ''
+    },
+    geometry
+  }
+}
+
+/*
+ * DF-1497: `updateFeature` writes both grid references before it applies the
+ * new geometry, so after a feature is updated the grid references still
+ * describe where the feature used to be. The three `updateFeature` grid
+ * reference tests below fail until that ordering is corrected.
+ */
+describe('getFeaturesManager', () => {
+  /** @type {GeoJSON} */
+  let geojson
+
+  beforeEach(() => {
+    geojson = { type: 'FeatureCollection', features: [] }
+  })
+
+  describe('addFeature', () => {
+    it('stores grid references for the added geometry', () => {
+      const { addFeature } = getFeaturesManager(geojson)
+
+      addFeature(
+        buildFeature('1', {
+          type: 'Point',
+          coordinates: [-0.1329571, 51.5027075]
+        })
+      )
+
+      expect(geojson.features[0].properties).toEqual(
+        expect.objectContaining({
+          coordinateGridReference: 'TQ 29684 79849',
+          centroidGridReference: 'TQ 29684 79849'
+        })
+      )
+    })
+  })
+
+  describe('updateFeature', () => {
+    it('recalculates the grid references of an updated point', () => {
+      const { addFeature, updateFeature } = getFeaturesManager(geojson)
+
+      addFeature(
+        buildFeature('1', {
+          type: 'Point',
+          coordinates: [-0.1329571, 51.5027075]
+        })
+      )
+
+      updateFeature('1', {
+        type: 'Point',
+        coordinates: [-0.1497151, 51.5025274]
+      })
+
+      expect(geojson.features[0].properties).toEqual(
+        expect.objectContaining({
+          coordinateGridReference: 'TQ 28521 79799',
+          centroidGridReference: 'TQ 28521 79799'
+        })
+      )
+    })
+
+    it('recalculates the grid references of an updated line', () => {
+      const { addFeature, updateFeature } = getFeaturesManager(geojson)
+
+      addFeature(
+        buildFeature('1', {
+          type: 'LineString',
+          coordinates: [
+            [-0.1329571, 51.5027075],
+            [-0.1324662, 51.5006911]
+          ]
+        })
+      )
+
+      updateFeature('1', {
+        type: 'LineString',
+        coordinates: [
+          [-0.1497151, 51.5025274],
+          [-0.1404592, 51.5022288]
+        ]
+      })
+
+      const { properties } = geojson.features[0]
+
+      // First point of the new line
+      expect(properties.coordinateGridReference).toBe('TQ 28521 79799')
+      // Midpoint of the new line (-0.14508715, 51.5023781)
+      expect(properties.centroidGridReference).toBe('TQ 28843 79791')
+    })
+
+    it('recalculates the grid references of an updated shape', () => {
+      const { addFeature, updateFeature } = getFeaturesManager(geojson)
+
+      addFeature(
+        buildFeature('1', {
+          type: 'Polygon',
+          coordinates: [
+            [
+              [-0.1430274, 51.5012331],
+              [-0.1424662, 51.5006911],
+              [-0.1416921, 51.5010163],
+              [-0.1430274, 51.5012331]
+            ]
+          ]
+        })
+      )
+
+      updateFeature('1', {
+        type: 'Polygon',
+        coordinates: [
+          [
+            [-0.1497151, 51.5025274],
+            [-0.1404592, 51.5022288],
+            [-0.1400755, 51.5020198],
+            [-0.1497151, 51.5025274]
+          ]
+        ]
+      })
+
+      const { properties } = geojson.features[0]
+
+      // First corner of the new shape
+      expect(properties.coordinateGridReference).toBe('TQ 28521 79799')
+      // Centroid of the three distinct corners (-0.1434166, 51.5022587)
+      expect(properties.centroidGridReference).toBe('TQ 28959 79780')
+    })
+
+    it('reduces the precision of the updated geometry to 7 decimal places', () => {
+      const { addFeature, updateFeature } = getFeaturesManager(geojson)
+
+      addFeature(
+        buildFeature('1', {
+          type: 'Point',
+          coordinates: [-0.1329571, 51.5027075]
+        })
+      )
+
+      updateFeature('1', {
+        type: 'Point',
+        coordinates: [-0.14971510866865856, 51.50252738875241]
+      })
+
+      expect(geojson.features[0].geometry.coordinates).toEqual([
+        -0.1497151, 51.5025274
+      ])
+    })
+
+    it('returns undefined and changes nothing when the feature is unknown', () => {
+      const { addFeature, updateFeature } = getFeaturesManager(geojson)
+
+      addFeature(
+        buildFeature('1', {
+          type: 'Point',
+          coordinates: [-0.1329571, 51.5027075]
+        })
+      )
+
+      const result = updateFeature('unknown', {
+        type: 'Point',
+        coordinates: [-0.1497151, 51.5025274]
+      })
+
+      expect(result).toBeUndefined()
+      expect(geojson.features[0].properties.coordinateGridReference).toBe(
+        'TQ 29684 79849'
+      )
+    })
+  })
+})
+
+/**
+ * @import { GeoJSON } from '~/src/client/javascripts/geospatial-map.js'
+ * @import { Feature, Geometry } from '~/src/server/plugins/engine/types.js'
+ */
diff --git a/test/client/javascripts/map.test.js b/test/client/javascripts/map.test.js
index 3952f7611..95f8b3edf 100644
--- a/test/client/javascripts/map.test.js
+++ b/test/client/javascripts/map.test.js
@@ -1127,16 +1127,18 @@ describe('Maps Client JS', () => {
             type: 'Polygon',
             coordinates: [
               [
-                [0, 0],
-                [1, 1],
-                [2, 2]
+                [-0.1406682, 51.5021389],
+                [-0.1395772, 51.5002887],
+                [-0.1293066, 51.5013894],
+                [-0.1305105, 51.5060496],
+                [-0.1406682, 51.5021389]
               ]
             ]
           },
           properties: {
             description: "St James' Park",
-            coordinateGridReference: 'TQ 29200 79762',
-            centroidGridReference: 'TQ 29560 79824'
+            coordinateGridReference: 'TQ 29150 79772',
+            centroidGridReference: 'TQ 29541 79818'
           }
         }
 
@@ -1247,14 +1249,14 @@ describe('Maps Client JS', () => {
 
         // Manually invoke interactMarkerChange callback with a new point
         const updatedPointArgs = {
-          coords: [0, 0]
+          coords: [-1.3260764, 53.2366094]
         }
 
         interactMarkerChange(updatedPointArgs)
 
         expect(mockAddMarker).toHaveBeenLastCalledWith(
           '6d67810c-7228-4f71-b6ec-0d16b132fcd7',
-          [0, 0]
+          [-1.3260764, 53.2366094]
         )
 
         expect(geospatialInput.value).toBe(
@@ -1262,9 +1264,14 @@ describe('Maps Client JS', () => {
             [
               {
                 ...features[0],
+                properties: {
+                  ...features[0].properties,
+                  coordinateGridReference: 'SK 45077 71275',
+                  centroidGridReference: 'SK 45077 71275'
+                },
                 geometry: {
                   ...features[0].geometry,
-                  coordinates: [0, 0]
+                  coordinates: [-1.3260764, 53.2366094]
                 }
               },
               ...features.splice(1)